Stereotype plate clamping means



Dec. 22, 1936. H. A. w. woon STEREOTYPE PLATE CLAMPING MEANS 5 sheets-sheet 1 origina; Filed Decfzl, 1952 aan? m @wv/M mw. NN, NN mw. @@INNMNH NNQN.

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. rllnl. I E Y RN u M Q @l Patented Dec. 22, 1936 PATENT OFFICE STEREOTYPE PLATE CLAMIING Henry A. Wise Wood, New York, N. Y., assignor tu Wood Newspaper Machinery Corporation,

New York, N. Y., a corporation of Virginia Application December 21, 1932, Serial No. 648,176 Renewed February 6, 1935 4 Claims.

The principal object of this invention is to provide means for clamping stereotype printing plates on a printing cylinder, or other supporting member, in such a way that they are held in place at points inside their edges andV to provide a clamping means: to` be used in cooperation with the usual edge clamping members for holding the plates down at internal points; also to provide a n construction for these purposes which is simple and canV be brought intooperation by a longitudinal motion of the clamp as it is locked on the plate cylinder.

Other objects and advantages'of the invention will appear hereinafter.

Reference is to be had tothe accompanying drawings, in which Figll is a radial longitudinal sectional View of apart of a printing cylinder with a plate clamped thereon, showing a. preferred embodiment. of this invention;

Fig'. 2..is a sectional view onl the line 2-2 of Fig.. 1;

Fig.` 3l is a view similar to Fig- 1 on enlarged scale; i

Fig. `l is aview. similar to Fig. 3 showing the plate clamp moved to unclamping position;

Fig. 5 is a. similar view showing the parts in the position in which the plate can be removed from the cylinder in a radial direction;

Fig. 6 is a view similar to Fig. 1, showing a modification;

Fig. 7 is a similar view showing the plate unclamped;

Fig. 8 is a similar view showing a third form;

Fig. 9 is a transverse sectional view on the line 9-9 of Fig. 8;

Fig. 10 is an edge view of a printing plate as cast; and

Fig. 11 and Fig. 12 show how the undercut recess is produced.

In printing presses where stereotype plates are used, it is customary to secure these printing plates to the plate cylinder by beveled clamps operating against the curved edges of the plates. In some cases the straight edges of the plates also are clamped down on the cylinder. The trend in newspaper printing plants has been toward higher speeds and the edge clamping means have not proved to be sufficient to hold the plates securely under such conditions. This invention is made for the purpose of providing additional clamping means engaging the plates at other places than at the edges.

In the form shown in the first five figures, the usual plate cylinder is shown carrying the usual margin bars 2 which extend along the straight edgesY of the plates. The usual center ring 3, movable center clipl 4 and movable enclclamp 5 are employed. Two plates P and P are shown as being clamped on the cylinder by these means.

It is alsoI customary to provide a supporting block 6 on the plate cylinder I. Against this block one end of a clamping spring 'I' engages and it forms an abutment for theend of this spring. This. spring isV shown as surrounding a rod 8 and on this rod is a collar which the free end of the spring engages to forcethis rod under spring pressure to the right. The left end of the rod is threadedly connected with the end clamp 5 so A that this clamp is forced to the right by this spring asl usual to force the plate to the right and clamp both plates. Of course, some well known means is used for pulling the clamp portion away from the plate against the pressure of the spring I for unlocking the plates. No such means isv shown herein as this invention relates tov other features andit is` disclosed. in my prior application, Serial No. 576,522, filed November 21,. 1931.

- A clampingl strip 9 is provided which is of T-shape in crossf section and nts in` a T-slot Hl longitudinally' arranged in the plate cylinder l. This clamping strip 9 is provided with projections Il which are slanted toward the outer end of the cylinder. They fit into recesses I2 in the under side of the plate, which recesses are provided with slanting undercut ends for receiving the projections Il.

An extension block I3 is secured to the clamping plate 9 as by screws I4. This alords a stop against an integral wall I5 in the plate cylinder I. This clamping strip also serves as an abutment against which a spring I6 may act to force the clamping strip 9 to the left as shown in Fig. 1.

When the end clamp 5 is withdrawn, the clamping strip 9 moves to the left with it of course until the extension piece I3 abuts against the wall I5. 'I'hat stops the movement of the parts 9 and I3.

A similar construction is shown underneath the plate P' working in the same way. It is apparent that with the movement of the plate clamp 5 to the left, the plate P will travel to the left until the clamping strip 9 reaches the end of its stroke. Any further movement of the plate P to the left will release the bevel projections carried on topof the clamping strip 9 and permit the plate to be removed in a radial direction as indicated in Fig. 5. In like manner the center clip 4 may be moved to the left to permit the plate P' to be removed. 'I'his clamping strip in the form shown in the first five lgures may be essentially the width of the slot in the cylinder.

In Fig. 6 a modication is shown operating in the same way, except that each of the projectionsV I1 is individually supported and springpressed by a spring I9 and collar 20 pinned to a rod 2| which is fixed in the plate cylinder. This type of construction provides means for compensating for any inaccuracy in Imachining between the several recesses in the plates or for any diierences which may-occur due to unequal shrinkage of the plates'V when cooling from the recently cast condition.

The projections l1 are shown to be approximately the-same width as those shown in Fig. 1. Fig. 7 shows the same form as shown in Fig. 6 with, the plate freed so that it can be removed. This demonstrates the manner in which the beveled extensions l1 release the plate.

In Fig. 9 another modication is shown in which an extension 22 of the clamping strip is provided essentially in the form of a ring, that is, a half ring. This may be used to clamp the plate along a large part of its underneath periphery and, although it cannot be fully it canv extend through an arc less than that. This covers essentially one-half of the length of the plate.

In Fig. 10 is shown a plate P as cast for this purpose and in Figs. 11 and 12 the manner in which the recess can be undercut to the shape as shown in Figs. 1 and 6. This is done by a hook tool 23 attached to the usual shaving knife 24. This tool will machine out the proper bevel in the plate to accommodate these interior clamping devices.

It will be seen therefore that in addition to the straight and beveled edge clampingdevicesl, or either of them, means is provided to clamp the plate on its inner area at points between the edges which can be released just as easily as has been the case heretofore and is equally simple.

Although I have illustrated and described only three forms of my invention, I am aware of the fact that other modications can be made therein by any person skilled in the art without'departing from vthe scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to all the'details of construction herein shown and described, but what I do claim is: Y

1. In a device for clamping a printing plate on a printing cylinder, the combination of a longitudinally movable end clamp for engaging the outer edge of the plate to clamp it, yielding means for normally holding the end clamp in clamping position, means for clamping the plate on its under side between the edges, and yielding means for operating said clamping means to assist in holding the plate.

2. In a device for clamping a printing plate on a printing cylinder, the combination of a longitudinally movable end clamp for engaging the outer edge of the plate to clamp it, yielding means for normally holding the end clamp in clamping position, a clamping strip movable in the same direction as the end clamp and having means for clamping the plate on its under side between the edges, and yielding means for forcing said clamping means toward the end clampl to assist in holding the plate.

3. In a device for clamping a printing plate on a printing cylinder, the combination of an end clamp movable inwardly along the cylinder for clamping the outer edge of the plate, yielding means for forcing the end clamp inwardly, a clamping strip under the plate having inclined projections thereon for engaging the under side of the plate, and yielding means for forcing the clamping strip outwardly along the cylinder to hold the plate at points between its edges.

4. In a device for clamping a printing plate on a printing cylinder, the combination `of an end clamp movable inwardly toward the'cylinder to clamp the outer edge of a plate, a plurality of clamping strips under the plate, each having a projection located slantingly thereon for engaging an undercut recess in the plate and yielding means for forcing said strips, each independently, in a direction toward the outer edge of the plate. HENRY A. WISE WOOD. 

